Method of producing photographic dyestuff images



Patented Feb. 23, 1937 umrso STATES who!) or 2.071.688 rnonucmc Pno'roommo ores-rue moons lliaGuponm-ullclnllelgium No mum. Application Deccmbcr I, :2,

Serial No. 646.212. 1981 Claim!- This invention relates to a method ot'producing photographic dyestuil images. It has alrea y been proposed to incorporate dyestufls in the senntized layer and to convert the sensitized 5 layer into the dyestufl image after the production oi the photographic image. In this connection the absorption oi the dyestuli acts in disturbing fashion upon the exposure or the production of the copy. To overcome this, various methods 1o have already been proposed" in which dyestufl arming substances are employed.

These however, all possess the disadvantazHhich will be explained in greater le aii ater-that the same are too complicated,

as .he formation of the dyestufl being directly or indirectly dependent on the silver deposit.

The formation of the dyestui! takes place either through the medium of the silver image or its products of conversion. The process oi forma- 29 tion first referred to occurs principally in the.

case of cbromogeneous development. Methods oi the second kind present a greater variety.

Practically all of these. however, are accompanied by the feature that before the actual yestufi forming reaction takes place the conversion oi the silver image occurs over various intermediate For example, the silver image is converted into lead chi-ornate. This is performed in suchiashicn that at first the silver 34 image is converted into term-cyanide of silver,

the fem-cyanide of silver into term-cyanide of lead the retro-cyanide of lead into lead chromate,

and from the lead cbromate the chromic acid a is afterwards employed for oxidizing some suit able dyestuif forming substance, ior pie leuco esters of vat =2 It has also been proposed to produce am dyestui! images along similar lines and also to employ other dye-iorm-V addition to the methods referred to generally in theabovehavealsobeenmadetotan sothegelaiinelayeriikewisethroush the medium.

of the silver lipase-and to allow the formation of the dyeotufl to'take place subsequently at the tanned or the untamed points. These methods. however. are confined right from the commence- -l ment to one single layer, since, when w ns the In Germany December I,

tanning process in conjunction with a plurality of layers, a tanned point. on the surface would also block the points situated thereunder.

The number of compounds, which together with the silver image or throughthe medium of the 5 same result in a dye-forming compound are very small, and great limitation is imposed right irom the commencement in the selection oi the dyestufl forming substances and also the substances initiating the formation of the'dyestufis. 10

The disadvantages and drawbacks referred to in the above are overcome by the present invention.

The essence of the invention resides in principle in forming the dyestufl." diflusely in the entire 15 layer by a desired reaction wholly independently of the silver image, and to then destroy the resulting. dyestuil atthe points of the silver deposit or at the points which are free of deposit. Ibis principle is employed in its broadest aspect, the same being open to modification insofar as in accordancewith the invention it is also possible to destroy the dyestufl. forming substance itseli by the means used in the new process before the diffuse dyestufl formation takes place. The present invention oilers a very wide choice as regards the dyestuils and dyestufi iorming substances to be employed. Thus, for example,

practically all reactions of the dyestufi formation on the photographic image are capable of so use, with the exception of those. the employment of which in'the photographic layer is fundamentally precluded, owing to the fact that the photographic layer will not withstend'the temperature or duration olthe reaction, which may 35 be necessary, or a too complicated and lengthy conversion would be necessary ior tormation of the dyestuil, or also that dyestufl forming substances would require to be employed, which might exert detrimental eflect on the silver halide g; or the finished silver imase. Accordingly the v dyestufi is formed in the layer independently oi the silver image after the exposure and before or after the development, or also simultaneously 'therewith, and the colored imaie results from 5 destruction of the formed dyestui! either at the points of the silver deposit or at the points which are ireeoi silver.

It is acoordinsiy much more simple to destroy "the amount oi dyestuitthan to form the, dyestui! so in proportion or inverse proportion to-the metal deposit. The destruction oi the 'dyestui! is. periormedprincipally with the means set-forth in my prior Patent No. 2,020,775, patented November l2, 1935, and in my copendino' application '55 place in the entire layer.

from the said patent. These result in one single bath in a positive or negative dyestuif image from the difiusely colored metal deposit image dependent on the particular means employed. The destruction of the dyestuff itself may, holy ever, also take place in accordance with any other desired process, for example by way of coupled or induced reactions,,or by the selective bleaching of a mordanted or tanned image. However, the methods last referred to are somewhat tedious, and it is preferable to perform destruction of the dyestuilf in one single bath, since, apart from loss of time, the formation of the image is better capable of control than if the-image requires to pass through a plurality of interme-' diate reaction stages up to destruction of the dyestufi.

The photographic layer or the plurality of layers, which are situated in superimposed fashion or poured one over the other, and are sensitive to different colors, contain or receive one or more dyestuif forming components. These are then converted by reaction of a desired kind into the dyestuif, whereby, generally speaking, a diffuse and quantitative dyestufi formation takes substances may also be present in diiferent colorsensi-tive particles of emulsion situated discontinuously one over or beside the other, such as result from. atomization or the re-emulsifying of different emulsions. Alternatively the dyestuff components may be applied to a layer of silver halide by pressure, atomization or similar measures, possibly admixed with filter dyestuffs and sensitizers. The different color-sensitive emulsions or particles of emulsions naturally contain in addition to the dye-forming substances the sensitizer and possibly also a filter dyesufi. In the majorityof casesit is suilicient to employ a yellow or red filter dyestufi.

The dyestufi forming substances, in the same manner as the dyestuifs in general, may belong to different chemical groups of substances, and will usually be of organic or inorganic kind. The examples of dyestufi-forming substances may preferably be divided according to the diflerent known groups of dyestuffs. In the first place reference will be made to inorganic substances.

Diiferent metal salts may be incorporated in the layer as far as possible in neutral or insoluble form, for example an insoluble iron or lead salt. The production of the dyestufi occurs by a desired reaction, for example a ferrosalt is converted with ferri-cyanide of potassium, toform Prussian-blue, or the lead salt is converted with a chromate to form lead chromate. A difluse blueor yellow image results in the layer. If a solution is used, acting indestructive fashion on the dyestufi' in the presence of the silver image, possibly a solution according to the examples quoted in my prior patent above referred to, a reduction takes place by reason of this bath at the points of the silver image. The resulting Prussian blue or lead chromate, respectively, is destroyed at the points of the silver image. Ibis in the present case constitutes a reduction, and in this man- The dyestuff forming.

the points free of silver. treat these after the oxidation which produces a diiiuse coloring with thiocarbamide. In;; th1s into a reversed image. Numerous other inorganic deposits or metal salts may be produced in this manner, which are then destroyed or decolored by oxidizing or reducing agents.

Among dyestufis of'an organic kind dyestuil's of practically all groups are capable of being produced in the layer, viz, nitro dyestuifs, nitroso dyestuffs, chinonimine dyestuffs, vat dyestuffs etc. In the case of the basic dyestuifs, the leuco base is incorporated in the layer, and this subsequently oxidized diffusely in the layer to form the dyestufl. The leuco base itself-may be in-' corporated in the layer in the form of a finely divided deposit, a salt of phosphortungstic acid,

molybdic acid or tannic acid. The oxidation to form the dyestuff takes place after development and fixing, and the dyestnfi is then destroyed at the points of the silver deposit or at the points free of deposit. In this connection, the oxidation of the leuco base to form the dyestufi and subsequent destruction of the dyestufi may take place in one single bath. Naturally, for the production of multicolor images, a plurality of differently colored leuco bases may be also poured in diflerent color-sensitive layers one over the other, and the reaction performed simultaneously in several layers.

The production of multicolor images in the plurality of layers, etc., as already referred to in the above, constitutes the main field of use of this process and applies to all examples set forth in the following:

There may be produced in the layer a nitro dyestuff, for example naphtholgreen Schultz Farbstoiftabellen, 5th ed. No. 4, there being incorporated in the layer either a farm salt or 1- nitro-2-naphthol-6-sulfonated sodium, or in place of the sodium salt another salt, for example 2- phenyl-4-amino-chinoline salt, and a ferro salt thereupon allowed. to act. Naphtholgreen is formed. If a solution of thiocarbamide is allowed to act on the resulting naphtholgreen, a reversed stroyed at the points of the silver image. The

- procedure, however. may also be such that l-nitroso-2 naphthol-fi-sulfonated salt is subjected to the action of this solution prior to the reaction with the iron salt. In this case, the-nitroso group is reduced to the amino group at the points of the silver image and dyestufi is formed only at the unreduced points. adapted by incorporating a ferri salt in the layer and reducing this to form salt at the points of the silver image and then allowing the naphthalene compound referred to in the above to act on the image afterwards. In this manner a positive green image is obtained only at the points of the silver.

The reverse step-may also be 1 It will be apparent from these'examples that formance and the avoidance of numerous inter- I mediate reaction stages.

The process referred to in association with basic leuco substances also refers to leuco esters and ester salts and also ethers of vat dyestuffs and other preliminary stages of these dyestuffs of equivalent eflect. ,Together with the oxidation of the leuco ester, etc., to form the dyestufl, there may also be. performed destruction of the dyestuif atthe points of the silver deposit or at It is also possible.to

reducing agents, for example grapesugar, are

present in the solution, which prevent the reforming or reoxida'tion of the dyestufi in the layer itself (or which, for example borlc acid, constitute with the formed leuco body a soluble complex), or the leuco dyestufi again being esterized in the layer to form an air-resisting chemical body, for example bymeans of benzylizing ammonium bases, such as dimethylphenyl'benzyl-ammonium salt'or the corresponding sulphur acid of this salt.

Chinomine dyestufls may also be produced in the layer by the oxidation of corresponding leuco compounds of these substances, or the same may be allowed to form in the layer by interaction of the components or oxidation of the components oi. the chinomine dyes oi. indo-phenols, indoanllines, indamines, a'zomethines, oxazines,

thiazines, indothiophenols, etc., possibly also the coupling of nitroso bodies with phenols, etc. The

destruction of the dyestufl takes place either by means of oxidising baths, the oxidation already commenced simply being continued up to destruction of the dyestufl' at certain points, or for example an, indophenol being reduced to corresponding diphenylamine by local reduction. The

production of the dyestuff may be so performed that-nitrosodimethylaniline acts in the layer, for example on l-naphthol (or a difficultly soluble naphtholate), and the dyestuif subsequently reduced at the points of the silver image. However, the formation of the dyestufl, as disclosed by the above examples, may also take place by the fact that nitrosodimethylaniline is introduced into the layer and the latter reduced at the points of the silver image, 1. e. made incapable of coupling, and l-naphthol then allowed 'to act on the layer.

It is also possible to produce an oxazine in the layer. For example, resorzene is allowed to act on nitrosomethylaniline in the presence of tanponents may be incorporated in the layer and" then developed with a diazonium salt. For example, two layers are poured one upon the other.

The one contains a difilcultly soluble salt (2- phenyl-4-amino chinoline saltl of SS-acid, the

other layer, the salt of G-acid. This is then.

coupled after the development of the silver image with 2-diam-5-dimethylamino-4-methyl-phenyl sulfon. In the one layer there is formed a red and in the lower layer a blue dyestuif, which ditlu ely colors the layer. Following thereon the silver image ,is treatedwith a dyestufi destroying bath, which supplies a positive or negative image as desired at the points of the silver image or at the points which are free of deposit. ternatively, durable diazo compounds or other durable products of conversion of the diazo compounds, such as diazo-amino compounds, triazenes or nitrosamines may be added to the layer itself, with or without coupling components. These dyestufi-forming substances, such as. nitrosamlnes 'or diazonium compounds, may be destroyed at points prior to the coupling either by oxidation, or even morepreferably by reduction, the nitrosamines or diazonium compounds iorth in the above.

3 being reduced at the points or the silver image to yield, for example the hydrazines, which, as well known, do not couple.

- It is,-however, also possible to incorporate in the layer hydrazines and to convert these subsequently into diazo compounds and then develop I azo dyestuffs, or different diazonium' compounds are incorporated in the layer or produced in the layer by diazotation, resulting with a common H coupling componentin an azo dyestufi.

To repeat briefly-there accordingly takes place after the ordinary development a second development with a diazonium salt, whereby the different azo components are coupled to form difierently colored azo dyestufis, or a diamnium compound is present for example in the layer, and this subsequently developed to form an azo dyestufi with an alkaline phenol. The developer itself may be contained in the original developer, for example the coupling body may be added to the alkaline developer, whereby simultaneously with the silver image there is produced a layer colored difiusely throughout with dyestufi. The destruction of the dyestuii? at points "then occurs subsequently, as described in the above. It is also possible to incorporate aromatic amines in the layer and to couple these to form azo dyestuffs by the action of nitrous acid and possibly rendering alkaline, which dyestufis diffusely color the layer, and the image then results by destruction of the dyestufl' at certain points, as described in the above.

It is also possible to employ substances which are merely relatively colorless. A green-sensitive layer which requires to be exposed to a green ray of light is for example also colorless as regards this green ray, if coloring is performed with a yellow dyestuif. The coloring of red-sensitive layer is also colorless as regards red rays of light, when coloring is performed, for example with a red-violet dyestufl.

Suitable for this purpose are, for example, the developing dyestuils. These dyestuffs may then be diazotized in the layer by treatment with an acid sodium nitritesolution and subsequent coupling and converted into diiferent colored compounds, for example in the manner I have already described previously in the French specification No. 702,615. The destruction of the dyestufi at points then occurs subsequently, as set For example, the green'v sensitive layer is colored with a yellow dyestuif,

such as amido-azobenzol (or its sulfo-acid).

The underneath layer is colored with diazo pure blue B Ullmann, Enzyklopdie der .Technischen Chemie, 3. ed. (1929) VOLIII p. 659. The dyestuffs are subjected to dlazotization with sodium nitrite violet a blue dyestuif. Naturally it is also pos sible to employ combined layers, there being used for the yellow image a practically colorless component, i. e. dlazo-light yellow Flora-David, Kiinstliche Organische Farbstoife, Berlin 1926,

page 154, and for the underneath layers colored components. It is, however, also possible to vary or deepen in color through the medium of coupling by treatment with a diazonium solution a dyestufi incorporated in the layer.

The dyestuiI-forming substances which are incorporated in the emulsion may be developed with an acid methylene group may serve for bro-- duction of either an azomethine dyestufl' or an azo dyestuff.

On the other hand the layers consisting of one or more .superimposed or otherwise combined layers, for example layers or equivalent arrangements of multi-layer material situated on both sides of a support, as mentioned above, may contain dyestufi-forming substances, which supply dyestuifs belonging to different groups. For example, a leuco ester and a substance forming with the developing dyestuii an amino compound or an azo dyestufi may be present in the layer. If now diazotizationv is performed with sodium nitrite, the-leuco ester is oxidized to form dyestuff and at the same time the amino compound diazotized. In the subsequent alkaline coupling bath there is then formed inthe layer an azo dyestufi, which contains the azo components. However, it is possible at the same time for an oxidation agent to simultaneously oxidize a leuco body and form a mineral dyestuff; for example, there is formed in a layer containing a lead salt lead chromate, while in the other part layer or in the particles of the layer a leuco ester is oxidized to form dyestui! by the chromic acid. The destruction of the dyestufl thus formed in the layer may then be performed in desired fashion according to the one or the other patents which I have previously obtained.

The light-sensitive layers prepared in the above manner may be employed for ordinary or also color photography. According to the above method it is possible to produce .a reversed In particular these ponents are employed for the production of multicolor images, these being employed either in immediate fashion for exposure purposes, or also as copying material (iorrexample, diapositives, cinematograph films, paper images). As master imagesit is possible to employ either images or screen plates colored as desired, or copying may be performed in accordance with other methods,

similar coloring to the color-sensitiveness of the layer. It is furthermore possible to employ dyestufi-forming substances, whichimpart to the layer a color which is independentof the colorsensitiveness. These are employed primarily for the production of master images for the p of copying on colored layers.

It will be understood that no limitation is made to the particular embodiments described in the above. and that numerous modifications are quite possible within the meaning of the above description and the annexed claims without departing from the spirit of the invention.

What 1 claim is: a 1. A method of producing from at least one light sensitive silver halide emulsion layer arranged on a support and having incorporated therein dyestufl' forming substances. photographic dyestufl images by the use of both a chemical substance reacting with and producing a dyestuff from the said dyestuff forming substances at all points where such dyestufl forming substance is present and of a chemical substance which locally destroys the coloring matter in proportion to the metallic silver present in the layer, which consists in exposing and developing the light-sensitive material and finally removing the silver image in a known manner after the formation of the dyestuff image, a solution of the dyestufl-producing substance being applied to the material at a point in theprocess after exposure, and a solution of the locally destroying agent being applied to the material at a point in the process not prior to development, and not after the removal of the developed silver image. 1

2. A method of producing photographic dye-. stufl images from at least one light sensitive silver halide emulsion layer arranged on a support and having incorporated therein dyestufi forming substances, by the use of both a chemical substance reacting with and producing a dyestufl from the said dyestufi forming substance at all points where such dyestufi forming substance is present and a chemical substance which locally destroys the dyestufl forming substance in proportion to the metallic silver present in the layer, which consists in exposing and developing the light sensitive material, applyin a solution containing a substance 'for locally destroying the dyestufl-forming substance, at a point in the process including development and the subsequent steps, applying thereafter; a solution of the dyestuff-producing substance, 'and finally removing the silver image after the formation of the dyestuflf image in a known manner.

3. A method of producing photographic dyestufi' images from at least one light sensitive silver halide emulsion layer arranged on a support and having incorporated therein dyestuff- Vforming substances capable-of being destroyed by oxidation, by the use of both a chemical substance reacting with and producing a dyestufl from the said dyestufl. forming substances at all points where such dyestufl components are present and a chemical substance of oxidizing. 1 properties which locally oxidizes and thereby destroys the dyestun' forming substance in proportion to the metallic silver present in the layer, which consists in exposing and developing the light sensitive material. applying a solution containing the oxidizing agent locally destroying the dyestuft forming substance at a point in the process after development and the subsequent steps and applying thereafter a-solution of the dyestuft producing substance, and finally 11-. moving the silver'image after the formation of the dyestui! image in a known manner.

stuff images from at least onelight sensitive silver halide emulsion. layer arranged on a support and having incorporated, therein dyestuflforming substances capable of being destroyed by reduction, by the use of both a chemical substance reacting with'and producing a dyestuff present, and of a chemical substance of, reducing V 4; A method of producing photographic dyep s p I 2,071,688 properties which locally reduces and thereby destroys the dyestuff forming substance in proportion to the metallic silver present in the layer, which consists in exposing and developing the light sensitive material, applying a solution containing the reducing agent at a point in the process including development and the subsequent step applying thereafter a solution of the salts being capable of being transformed into dyestufis by the use of both a chemical substance reacting with and producing a dyestufi from the said inorganic salts at all points where such salts are present, and of a chemical substance which locally decomposes the said inorganic salts, in proportion to the metallic silver present in the layer, which consists in exposing and developing the light sensitive material, applying a solution containing a substance locally decomposing the inorganic salt at a point in the process including development and the subsequent steps, applying thereafter a solution of the dyestuff-forming substance, and finally removing. the silver image after the formation of the dyestufi image in a known manner.

6; A method of producing photographic .dyestufi images from at least one light sensitive silver halide emulsion layer arranged on a support and having incorporated therein dyestufi forming substances, by the use of both a chemical substance reacting with and producing a dyestufi from the said dyestufi-forming substances at all points where such dyestuff components are present and of a chemical substance which locally destroys the dyestuff in proportion to the silver image present in the layer, which consists in exposing and developing the light sensitive material, applying a solution of the dyestuif-pro-' ducing substance to the material at a point in the process after exposure, then applying a solution containing the substance locally destroying the dyestufi, and finally removing the silver image after the formation of the dyestuil image in a known manner.

'l. A method of producing photographic dyestufi images from at least one light sensitive silver halide emulsion layer arranged on a support and having incorporated therein azo-dyestuiI-components, by the use of both a chemical substance reacting with and producing a dyestuf! from the said azo-dyestufi components at all points where such dyestufi' components are present, and of a chemicalsubstance which locally destroys azo-dyestufis in proportion to the silver image present in the layer,-which consists in exposing and developing the light sensitive material, applying a solution of the azo-dyestufiproducing substance to the material at a point in the process after-exposure then applying a solution containing, the substance locally destroying the azo-dyestuff, and finally removing the silver image after'the formation of the dyestuil'f image in a known manner. f

producing a dyestufi from the said organic salts, at all points where such dyestufi components are present and of a chemical substance which locally destroys the dyest'uif produced in proportion to the silver image present in the layer, which consists in exposing and developing the light sensitive material, applying a solution of the dyestuif producing substance to the material at a point in the process after exposure, then applying a solution containing the substance locally destroying the dyestufl', and finally removing the silver image after the formation of the dyestuff image in a known manner. I

9. A method of producing photographic dyestufi images from at least one light sensitive silver halide emulsion layerarranged on a support and having incorporated therein leuco-bodies capable of being transformed into dyestuffs by oxidation, by the use of both an oxidizing substance reacting with and producing a dyestuff from the said leuco-bodies at all points where such dyestuff components are present, and of a chemical sub- 1 solution of the oxidizing substance being applied to the material at a point in the process after exposure, then applying a solution containing the substance locally destroying the dyestuif produced, and finally removing the silver image after the formation of the dyestuff image in a known manner.

10. A method of producing photographicdye stuff images from at least one light sensitive silver halide emulsion layer, arranged on a support and having incorporated therein diazo-compounds, by the use of both an azo-coupling component, coupling with and producing a dyestuif from the said diazocompound at all points where such diazo-compounds are present, and of a chemical substance which locally destroys the azo-dyestuii in proportion to the silver image present in the layer, which consists in exposing and developing the light sensitive material, applying a solution point in the process after exposure, then applying a solution containing the substance locally destroylng the azo-dyestuii', and finally removingthe silver image after the formation of the dyestufi image in a known manner;

11. A method of producing photographic dyestuif images from at least one light sensitive silver halide emulsion layer arranged on a support and having incorporated therein coupling components by the use of both a diazo-compound coupling with and producing a dyestuff from the said coupling components at all points where such coupling components are present and of a chemical substance which locally destroys azo-dyestufis in proportion to the silver image present in the layer, which consists in exposing and developing the light sensitive material, applying a diazo-compound to the material at a point in the process after exposure, then applying a solution containing the substance locally destroying the azo-dyestuff, and finally removing the silver image after the formation of the dyestufl image in a known manner. 7

12. A method of producing photographic dyestufi images from at least one light sensitive silver halide emulsion layer arranged on a support and dyed by a dyestufl capable of being converted into a differently colored azo-dyestufi, by the use of both a chemical substance reactin with and producing an allo dyestufl from the said dyestu'i! at all points where such dyestuil' is present and 01 a chemical substance which locally destroys one of the said dyestuffs in proportion to the silver image present in the layer, which consists in ex posing and developing the light sensitive material, applying a solution of the substance converting the dyestufl' to the material at a point in the process after exposure, applying a solution containing the dyestuildestroying substance at an optional point in the process after exposure, and

finally removing the silver image after the formation of the dyestui! image in a known manner.

13. A method of producing photographic dyestufi images from at least one light sensitive silver halide emulsion-layer arranged on a support and having incorporated a dyestuii containing a diportion to the silver image present in the layer, whichconsists in exposing and developing the light sensitive-material, applying a solution oi the dlazotizing substance and applying a solution of the coupling component to the material at a point of the process after exposure, applying a solution of the dyestui! destroying agent to the material at a point in the process after development, and finally removing the silver image after the formation 01'- the, dyestufl image in a known manner. v '7 l4. A light sensitive photographic material comprising a support and at least one silver halide emulsion layer on the saidsupport, the emulsion being iastiy dyed by diazo-iight-yellow.

l5. 'A light sensitive photographic material comprising a support and at least one silver halide emulsion layeron the said support, the emulsion being fastiy dyed by a practically colorless coloriorming substance possessing dyeing properties with respect to the emulsion layer.

BEL'A assrsa. 

